Dispensing pump



June 2, 1925. I 1,540,723

J. B. DAVIS DISPENSING PUME' Original Filed Nav. 7. 1921 INVENTOR ATTORNEYS i Patented .lune Z, 1925i insana JOI-IN B. DAVIS, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR T() GILBERT & BARKER MANUFACTURING COMPANY, A CORPORATION 0F MASSACHUSETTS.

DISPENSING PUMP.

.Tune 2, 1923.

Y 10 all t0/1.0m it may] concern.'

Be it known that I, Jol-IN B. Davis, a citizen of the United States, residing at Springfield, in the county of Hampden and Sta-te of Massachusetts, have invented new and useful Improvements in Dispensing Pumps, of which the following is a specilication.

This invention relates to improvements in dispensing pumps such as are commonly used for dispensing measured quantities of gasoline and the like.

The present application is a division of a copending application for U. S. Letters Patent of John B. Davis, Serial No. 513,- 369, filed November 7, 1921.

In one aspect, this invention is especially concerned with power-operated vdispensing pumps and has for its object to provide means for retarding the speed of such pumps as and when desired.

More particularly, the invention has for an object to provide, in a power-operated pump, a braking device which is manually operable at will to retard or stop' the pump.

As to this feature, the invention is an improvement in the mechanism disclosed in Il. S. Letters Patent No. 1,456,366, granted May Q2, 19h, on an invention of John B. Davis.

Other objects of the invention, together with the features of construction by which they are attained, will be apparent from the following description of the preferred embodiment thereof, illustrated in the accompanying drawings, in which Fig. 1 is a fragmentary sectional elevational view showing the invention as embodied in a power operated dispensing pump;

Fig. 2 is a top plan view of the braking device; and

Fig; 3 is a sectional view taken on the line 3-3 of Fig. 2.

Referring to these drawings: Fig. 1 shows a small portion of a vpower operated dispensing pump, of the type disclosed in the above named prior patent. The portion of the pump shown is suflic-ient to illustrate the application of the braking device thereto Divided and this application filed and reference to said patent may be had for a more complete disclosure of the pump. In Fig. 1, the pump cylinder is indicated at 5 and its piston rod at 6. The latter carries a cross head 7 to the ends of which are attached depending piston rods 8, disposed one on each side of piston f' rod 6.

These'piston rods 8 extend into compressed air cylinders'9, disposed one on each side of cylinder 5. By means disclosed in said patent, compressed air may be admitted to cylinders 9 to simultaneously liftthe piston rods 8 and thus the pump piston rod 6. The rods 8 are provided with `rack teeth on their back sides with which pinions 10 are meshed, these pinions being lined to a transversely disposed shaft 11, adapted to be manually turned, as by the crank handle 12, when desired. The pump mechanism described is encased in casing sections 13, 14; and 15 and, as shown in the prior patent, convenient access may behad to the section 1li in which the braking device is located.

The braking device is best shown in Figs. f2 and 3 and includes a drum 16 lixedly secured to the shaft 11 of the pump, and a Ybrake shoe 17 cooperating therewith together with means for applying the shoe to the drum. For convenience in assembling the drum upon its shaft the drum is made in two parts divided along an axial pla-ne and clamped together and to the shaft by bolts 18. To provide a maximum area of braking surface, the drum 16 is provided with a deep peripheral groove 19, while the brake shoe is formed with a segmental rib 20 the opposite sides of which are adapted to frictionallv engage the side walls of the groove 19. The side walls of the groove 19 are inclined toward the base of the groove and the side walls of the brake shoe rib 20 are similarly inclined to cooperatively engage the walls of the groove. No portions of the brake shoe 17 other than the inclined side walls of the rib 20 are adapted toengage with the brake drum and consequently the corresponding inclined portions of the rib and groove will be brought into cooperative relation by the application of pressure to the outer periphery of the brake shoe.

The means for applying pressure to .the brake shoe so as to set the brake comprises a lever 21 which is fulcrumed on a stud 22,

the latter projecting from a bracket 23 (Fig. 1) which serves to guide one of the operating rods 8 of the pump actuating mechanism. The fulcrumed end of the brake shoe operating lever 21 is forked, as shown, to embrace a pair of lugs 24C, which project from the outer periphery of the rake shoe and which in turn embrace the fulcrum stud 22 and serve to position the brake shoe radially with respect to the drum 16 and prevent displacement of the shoe. The forked lower extremities of the lever 21 are provided with cam faces 25 which are adapted to cooperate with flattened fac-es 26 on the brake slice to force the latter' into engagement with the brake drum. Normally the lever 21 is heldin its inop- 'erative pos-iti'onand the brake shoe is maintained disengaged from the brake drum by means of a coil spring 27 which Ais secured atl one end to the brake shoe and at its kopposite end to the lever 21'.

In operating the described pump by power, through the agency of the compressed air cylinders 9, the pump piston moves substantially uniformly throughout its' stroke from the time the power is applied to the cylinders 9 until it is disconnected therefrom, as is usual in all pow-er'- operated dispensing pumps so far as the inventor is aware. This arrangement has disadvantage over hand-operation where the pump piston'ma'y be controlled to move 'as' slowly as desired. Thus it frequently happens thatl the 'purchaser wishes .to fill a tankand yet is doubtful whether the tank will hol-d the entire 'quantity dispensed at one stroke of the pump; In such cases the purchaser naturally watches the tank and as it becomes near-ly full instructs the operatorof the dispensing` pump to pump slowly and to be ready to stop at an instants notice., With the power operated pump as generally provided the above condition cannot Ybe met and there is danger of over'- flowing the tank.

In accordance with the present invention thebraking device provides a means for controlling the speed of the pump piston while the latter is being operated by power so that the speed of the pump may be retarded as and when desired or, if necessary, stopped altogethervbefore it has completed its full stroke. When operating the pump by power, the operating rods 8 and the pump piston will be raised at a substantially uniform speed. At the same tim-e the shaft 11 and the brake drum 16 are Set in rotation. In case the operator is instructed to pump slowly he simply depresses the lever 21 until the operating rods 8 and the pump piston are retarded to the desired degree and if necessary the pump piston may be entirely stopped by the action of the braking device. In any event the braking device permits the operator to control the speed of the pump piston as and when desired, and particularly according to the desire of the purchaser, whereas without such device it is very diliicult to obtain the result desired. At best only an approximation of the result can be obtained by a series of stops and starts andthe operator does not have complete control of the situation at all times as he does when the braking device above described is employed. I

The invention has been disclosed herein, in an enfibodiment at present preferred, for illustrative purposes, but the scope of the invention is defined by the appended claims rather than by the foregoing description.

Claims:

1'. The combination with a brake drum having a peripheral groove therein,- of a segmental brake shoe having a part normally loosely received in said groove and held from lateral displacement thereby, an actuating cam for forcing said-part against the walls of the groove, a pin on which said cam is nivotally mounted, and a fork like portion on said shoe to straddle said pin.

2.--The combination with a brake drum having a peripheral groove therein, of a segmental brake shoe having a part normally loosely received inV said groove and held from lateral displacement thereby, an actuating cam for forcing said part against the walls of the groove, a pin on which said cam is pivotally mounted, a fork like portion on said shoe to straddle said pin, and a spring connecting said cam and shoe and tending to hold said part clear of the walls of said groove. p

3. The combination with a brake drum, of a segmental brake shoe, a lever having a forked end provided with a cam face, a fixed stud on which said lever is fulcrumed with said cam face in cooperative engagement with the outer face of said shoe and a pair of projections on the outerface of the shoe embracing sai-d stud andembraced by the arms of said forked end to locate said shoe with respect to the lever and drum.

.11. The combination with a brake drum, of a segmental brake shoe. a lever having a forked end provided with a cam face, a fixed stud on which said lever is fulcrumed with said cam face in cooperative engagement with the outer face of said shoe,la pair of projections on the -outer face of the shoe embracing said stud and embraced by the arms of said forked end to locate said shoe with respect to the lever and drums, and means normally maintaining said lever and shoe ininoperative position.

5. The combination with a brake drum having a peripheral groove therein, of a segmental brake shoe mounted in substantially vertical relation at one side of the 5 drum and having a part normally loosely received in said groove, an operating lever having a fork at one end, a Stud on Which said lever is pivoted adjacent said end, a pair of projections on said shoe intermediate the ends thereof embracing said stud 10 and embraced by the arms of said fork, and a spring connecting said lever to one end of said shoe.

JOHN B, DAVIS. 

